Method of forming tire casings



' Sept. 23. 1924.

1,509,366 T. MIDGLEY METHOD OF FORMING TIRE CASINGS Filed July IO. 1920INVENTOR memes Midglex. BY

' Patented Sept. 23, 1924.

- been suggested which core.

.. :rnoms MIDGLEY. BER COMPANY,

T'ES

1,509,366 PATENT OFFICE.

0F HAMPDEN,

0F 'CHICOPEE MASSACHUSETTS.

To all whom it may Be it known that I.

citizen of the United siding vented certain new MASSACHUSETTS, ASSIGNORTO. THE FISK RUB- FALLS, MASSACHUSETTS. A. CORPORATION OF ma'rnon orronumo 'rnm casinos.

Application filed July 10. 1 920. Serial K0. 395,328.

concern:

Trronus Minoan, a States of America, re-

at Hampdcn, in the county of Hampden' and State of Massachusetts,

have inand useful Improvements in a Method of Forming The Gasings, ofwhich the following is a specificas.

tion.

My invention relates to methods of buildand ing tire casings,

the

improvement of has for its object the tire casing itself and thefacilitation of its manufacture in various ways which will more fullyappear from the description and claims.

My invention will be described with particular reference to rings, inwhich 'Fig. 1 is a section the accompanying drawshowing the band offabric prior to the stretching operation;

Fig. 2 is a similar view at the completion of the stretching;

Fig. 3 is a section tioned on a core; Fig. 4 is a side ap aratus;'and

showing the band posielevation of the stretching *ig. 5 is a sideelevation of'the core on which the fabric is mounted for the finalshaping.

By my inventlon,

tuges, I am enabled to among other advanposition the fabric on the corewith the strain-resisting elements lying more accurately in their roperpositions for taking the strain whic l is im osed upon them in the useof the tire.

the unevenness of stretch,

rent I y reduce also both lateral and longitudinal, which is inherent inexisting processes. My invention also renders the operation of placingthe fabric on the core one requiring much less skill and strength thanThose skilled in this art recognize that the usual methods of hui ldingtire carcasses on formers or cores do not result in laminating thefabric or cord under the (lll'lUllS of stretch and tens on desired inresulting structure when In road use.

balanced coir the To overcome the objections many methods have rigidformer or omit all use of the Nevertheless the great convenience inusing a former or core during the building! thins of live tire iii thefactory cause of llw continue and handling operahus been the d and wideuse of the the usual methods.

stretch and tension and are then laminated on the former or core fortheir final association and desired relation in the tire. The

core-and the structure thus built upon it gives the desired conveniencefor factory operations and the tire so built is a better tire than tiresbuilt according to prior pro- Y cesses.

Myinvention is preferably practiced as follows: 7

A band of tire building material 10, preferably of bias cut rubberizedfabric or cord composed of one or more plies, and designed to form onlya. portion of the casing, is 10- ca'ted around an expansible member suchas an air tube 11 supported on a rim 12, mounted as on a buck 13.Preferably, in case socalled cord'fabric is used, the material is formedin bands comprising two single lies. The single-ply band illus ated inthe rawin'gs is, however, suitab e for use where square-woven fabric isemployed. A valve 14 serves forthe introduction of compressed air to thetube. The band so located is stretched and shaped by expanding the airtube into substantially the form shown in- Fig. 2 in which the maximumcircumference of the band is substantially 'that of the core or former,or of a previously partially built carcass. This expansion of the airtube against the band givcsthe latter both a circumferential and alongitudinal stretch and locates the strain-resisting elements in theproper positions to best bear the strains to be placed upon them invulcanization and will be substantia ly the position shown by the fulllines in 3. The Sin tched rub:

her of the band will contract, tending to draw the band closely a instthe core or former and what little ad itional shaping is necessary toget the ,band into the dotted line position of Fig. 3 can beaccomplished by pressing the edges of the band towards the core withoutany injurious lateral stretching-of the fabric such as was necessary -inprevious methods. The operation of applying successive plies in thismanner is continued until a. carcass of the desired thickness is builtup on the former or core, the bead material being added between theplies in any usual or desired way.

By the method described or its equivalent the fabric or cold of the tirecarcass is shaped and stretched at the same time and under betterbalanced tension conditions than in prior methods. The carcass is builtup with portions of its structure successively shaped and stretchedaccording to the shape and even tension conditions desired forthevalcanizing operation and for use. The carcass so built ma y then haveits trend and side walls applied in the usual ways or by stretching andshaping a rubber band in substantially the same manner as the fabricbands. My improved process presents many advantages in Ibo applicationof the outer portions of the casing, such as the breaker and cushionstrips, the tread, the side walls, and the chafin strip which surroundsthe bead; one of these advantages residing in the fact that theseelements can be applied as a unitary band, uiithout stretching the sidewalls and the chafing strip unduly. The tension given to the rubbertread band, however, is not of equal importance to that given to thefabric lies. The uncured tire casing thus ohtaine in better condition toundergo the various vulcanizing methods under pressure than tire casingsbuilt in other ways. The vulcanization may be performed in any usual ordesired way.

I claim:

1. The method of building tire casings on cores or formers comprisingforminga plurality of layers of fabric as endless bands, expanding, thebands with the central portions stretched more than the sides, andsuccessively applying the bands so treated to the core or former.

2. The method of building the carcasses on a ring core or formerconsisting in superposing upon the core or former successive endlesshands of tire-building material, each band being shaped to substantiallyits final form before being located on the core or former.

"the band to substantially the diameter of the core or former at itscrest leaving the side ortions of the band relatively less stretc ied,removing the band from the tube, and applyingthe hand to the-core orformer.

5. The method of applying fabric to cores or formers in the buildin oftire casings comprising forming the fa ric into a band of substantiallythe bead diameter of the .core or former, stretching the central portionof the band to substantially the crest diameter of the core or former,and applying the stretched fabric to the core or former.

G. The method of making a tire casing comprising forming an endless bandof extensible rubberized fabric, mounting the band upon an annular airtube, expanding the air tube until the central portion of the band issubstantially thecircumference of the core or former upon which thecarcass is to be built, removing the band from the air tube, positioningthe stretched band upon the core or former, pressing the side portionsof the hand against the core or former, stretching and positioningfurther bands in a similar manner until a carcass of the desiredthickness is obtained, adding bead re.- inforcements and an externalrubber coverin and vulcanizing the casing thus formed.

%. The method of building tire casings comprising forming a carcassstructure,'

forming the tread and side-Walls as a unitary endless band, pro-shapingsaid band to substantially the outer configuration of the carcass, andapplying the prc-shaped band to the carcass.

8. The method of building tire casings comprising forming a carcassstructure,

separately forming the tread, side-walls,-

breaker, and chafing-strip as an endless band of substantially the beaddiameter of the carcass, pre-shaping the band to substantially the outerconfiguration of the carcass, and'applying the so-shaped band to thecarcass.

THOMAS MIDGLEY.

